Provide views filter that limits based based on allowed bundles

@oknate the patch is failing to apply, see below for the error.

git apply -v /Patches/entity_browser/entity-browser-contextual-bundle-3039038-27.patch
Checking patch config/schema/entity_browser.schema.yml...
Hunk #1 succeeded at 251 (offset 21 lines).
Checking patch entity_browser.module...
Checking patch entity_browser.views.inc...
Checking patch src/Plugin/views/filter/ContextualBundle.php...
Checking patch tests/modules/entity_browser_entity_embed_test/config/install/editor.editor.full_html.yml...
Checking patch tests/modules/entity_browser_entity_embed_test/config/install/embed.button.bundle_filter_test.yml...
Checking patch tests/modules/entity_browser_test/config/install/entity_browser.browser.bundle_filter.yml...
Checking patch tests/modules/entity_browser_test/config/install/views.view.bundle_filter.yml...
Checking patch tests/modules/entity_browser_test/config/install/views.view.bundle_filter_exposed.yml...
Checking patch tests/src/FunctionalJavascript/EntityBrowserTest.php...
Hunk #1 succeeded at 41 (offset 4 lines).
Hunk #2 succeeded at 49 (offset 4 lines).
Hunk #3 succeeded at 92 (offset 4 lines).
Hunk #4 succeeded at 131 (offset 4 lines).
Hunk #5 succeeded at 173 (offset 4 lines).
Hunk #6 succeeded at 194 (offset 4 lines).
Hunk #7 succeeded at 209 (offset 4 lines).
error: while searching for:
  }

  /**
   * Tests the EntityBrowserWidgetContext argument_default views plugin.
   */
  public function testContextualFilter() {
    $this->createNode(['type' => 'shark', 'title' => 'Luke']);
    $this->createNode(['type' => 'jet', 'title' => 'Leia']);
    $this->createNode(['type' => 'article', 'title' => 'Darth']);

error: patch failed: tests/src/FunctionalJavascript/EntityBrowserTest.php:266
error: tests/src/FunctionalJavascript/EntityBrowserTest.php: patch does not apply
Checking patch tests/src/FunctionalJavascript/EntityEmbedTest.php...
Checking patch tests/src/FunctionalJavascript/InlineEntityFormTest.php...

The solution in #30 works great and provides a solution to the issue.

1. +++ b/entity_browser.views.inc
   @@ -22,6 +22,14 @@ function entity_browser_views_data_alter(&$data) {
   +
   +      $data[$base_table]['entity_browser_bundle'] = [
   +        'title' => t('Entity Browser Target Bundles'),
   +        'filter' => [
   +          'id' => 'entity_browser_bundle',
   +          'real field' => $entity_type->getKey('bundle'),
   +        ],
   

   should this have a condition on the entity type actually having a bundle key? e.g. users or paragraph library item might get confused if you try to add this.

2. +++ b/src/Plugin/views/filter/ContextualBundle.php
   @@ -0,0 +1,233 @@
   +      $container->get('request_stack')->getCurrentRequest(),
   

   you shouldn't inject the actual request but always the stack and get the current request when you need it. While maybe not likely in this context, subrequests result in the current request changing over time.

3. +++ b/src/Plugin/views/filter/ContextualBundle.php
   @@ -0,0 +1,233 @@
   +    // Disable element on config form.
   +    if ($this->currentRequest->attributes->get('_route') == 'views_ui.form_handler') {
   +      $form['value']['#default_value'] = array_combine(array_keys($form['value']['#options']), array_keys($form['value']['#options']));
   +      $form['value']['#disabled'] = TRUE;
   +      $form['value']['#description'] = $this->t('@entity types will update in response to entity browser context.', ['@entity' => $this->entityType->getLabel()]);
   +    }
   

   you can use \Drupal\Core\Entity\EntityType::getBundleLabel() here, then you get for example "Vocabulary" instead of "Term types" which is not a thing. And's it better for translation, e.g. in german it is "Inhaltstyp" and not "Inhalt Typ"

   However, there is no plural of that, but that is extremely tricky to properly translate anyway, so maybe you can reword this to avoid the plural?

   Just noticed that the parent uses "@entity types" too, I guess that's where it is from. Maybe you can just use the proper label for $this->valueTitle and avoid repeating it in the description? Or just create a core issue to improve the default there.

Thanks, didn't test but this is certainly useful and I think ready. Only did a pretty cursory review and a few parts look a bit weird ( that route checks, checkbox disabling and dependency overriding stuff) but I doubt there's a better solution.